Nonvolatile variable resistance element and method of manufacturing the nonvolatile variable resistance element

Abstract

According to one embodiment, a first electrode, a second electrode, and a variable resistance layer are provided. The variable resistance layer is arranged between the first electrode and the second electrode and contains a polycrystalline semiconductor as a main component.

1 . A nonvolatile variable resistance element, comprising:
 a first electrode;   a second electrode; and   a variable resistance layer arranged between the first electrode and the second electrode and comprising a polycrystalline semiconductor,   wherein   the polycrystalline semiconductor is polysilicon,   the first electrode is impurity doped silicon, and   the second electrode comprises at least one metal selected from the group consisting of Ag, Ti, Ni, Co, Al, Cr, Cu, W, Hf, Ta, and Zr.   
     
     
         2 . The nonvolatile variable resistance element according to  claim 1 , wherein the variable resistance layer changes from a high-resistance state to a low-resistance state when metal filaments become bigger along grain boundaries of the polycrystalline semiconductor, and changes from the low-resistance state to the high-resistance state when the metal filaments formed along the grain boundaries of the polycrystalline semiconductor become smaller. 
     
     
         3 . The nonvolatile variable resistance element according to  claim 2 , wherein the second electrode comprises a metal element that forms the metal filaments. 
     
     
         4 . The nonvolatile variable resistance element according to  claim 3 , wherein the metal filaments become bigger in the variable resistance layer when the metal element is supplied from the second electrode to the variable resistance layer, and the metal filaments become smaller in the variable resistance layer when the metal element is collected from the variable resistance layer to the second electrode. 
     
     
         5 . The nonvolatile variable resistance element according to  claim 2 , wherein the metal filaments are formed in the variable resistance layer when a set voltage is applied to the second electrode, and the metal filaments are eliminated from the variable resistance layer when a reset voltage is applied to the second electrode. 
     
     
         6 . (canceled) 
     
     
         7 . The nonvolatile variable resistance element according to  claim 1 , wherein the polycrystalline semiconductor has a hydrogen concentration of 10 19  cm −3  or higher. 
     
     
         8 . The nonvolatile variable resistance element according to  claim 1 , wherein the polycrystalline semiconductor comprises oxygen. 
     
     
         9 . The nonvolatile variable resistance element according to  claim 1 , wherein the polycrystalline semiconductor comprises OH groups in grain boundaries. 
     
     
         10 . The nonvolatile variable resistance element according to  claim 1 , wherein a grain diameter of the polycrystalline semiconductor is in a range of 2 nanometers to 5 nanometers. 
     
     
         11 . A nonvolatile variable resistance element comprising:
 a first electrode;   a second electrode; and   a variable resistance layer arranged between the first electrode and the second electrode, metal filaments being reversibly formed along grain boundaries of a polycrystalline semiconductor in the variable resistance layer,   wherein   the polycrystalline semiconductor is polysilicon,   the first electrode is impurity doped silicon, and   the second electrode comprises at least one metal selected from the group consisting of Ag, Ti, Ni, Co, Al, Cr, Cu, W, Hf, Ta, and Zr.   
     
     
         12 . The nonvolatile variable resistance element according to  claim 11 , wherein the second electrode comprises a metal element that forms the metal filaments. 
     
     
         13 . The nonvolatile variable resistance element according to  claim 12 , wherein the metal filaments become bigger in the variable resistance layer when the metal element is supplied from the second electrode to the variable resistance layer, and the metal filaments become smaller in the variable resistance layer when the metal element is collected from the variable resistance layer to the second electrode. 
     
     
         14 . (canceled) 
     
     
         15 . The nonvolatile variable resistance element according to  claim 11 , wherein the polycrystalline semiconductor has a hydrogen concentration of 10 19  cm  −3  or higher. 
     
     
         16 . The nonvolatile variable resistance element according to  claim 11 , wherein the polycrystalline semiconductor comprises oxygen. 
     
     
         17 - 20 . (canceled) 
     
     
         21 . A nonvolatile variable resistance element, comprising:
 a first electrode;   a second electrode; and   a variable resistance layer arranged between the first electrode and the second electrode and comprising a polycrystalline semiconductor, wherein the polycrystalline semiconductor comprises oxygen.   
     
     
         22 . The nonvolatile variable resistance element according to  claim 21 , wherein the polycrystalline semiconductor has a hydrogen concentration of 10 19  cm −3  or higher. 
     
     
         23 . The nonvolatile variable resistance element according to  claim 21 , wherein the polycrystalline semiconductor comprises OH groups in grain boundaries. 
     
     
         24 . The nonvolatile variable resistance element according to  claim 21 , wherein a grain diameter of the polycrystalline semiconductor is in a range of 2 nanometers to 5 nanometers.